STAT3 and acute promyelocytic leukemia: Mechanistically, leptin fortifies primary acute promyelocytic leukemia cells against apoptosis by activating signal transducer and activator of transcription 3 (STAT3) phosphorylation, mitogen-activated protein kinase (MAPK) signaling, and Leptin/LEPR receptor interactions—achieving maximum effect through intimate cell-to-cell contact [117].